1. Field of the Invention
The present invention relates to a tape drive such as a magnetic recording tape drive. In particular, the present invention relates to a guide roller utilized to guide a tape.
2. Description of the Prior Art
A pair of guide rollers is often incorporated in a magnetic recording tape drive, for example. The guide roller includes a roller body supported on a support shaft. The guide roller is designed to receive a magnetic recording tape at an outer cylindrical surface. A lower flange member is located adjacent the lower end of the roller body. An upper flange member is located adjacent the upper end of the roller body. The upper flange member is allowed to move in the axial direction of the roller body. The lower and upper flange members are designed to extend farther than the roller body in the radial direction from the longitudinal axis of the roller body. The lower flange member serves to define a reference position for the lower edge of the magnetic recording tape. The upper flange member is coupled to a restraint member fixed to the upper end of the support shaft, for example. An elastic member such as a coil spring is located between the upper flange member and the restraint member, for example.
When the magnetic tape is driven in the magnetic recording tape drive, the elasticity of the coil spring forces the upper flange member to urge the magnetic recording tape against the lower flange member in the aforementioned guide roller. The magnetic recording tape is thus allowed to travel along the reference position on the lower flange member. In this case, if the lower edge of the magnetic recording tape creases, the width of the magnetic recording tape narrows. The upper flange member forces the creasing lower edge of the magnetic recording tape to align with the reference position of the lower flange member. As a result, the servo track deviates from a predetermined reference position on the magnetic recording tape. A so-called off-track occurs. A magnetic head cannot follow the servo track on the magnetic recording tape. A tracking control cannot be realized.